Copyright
©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
Age-related impairment of esophagogastric junction relaxation and bolus flow time
Charles Cock, Laura K Besanko, Carly M Burgstad, Alison Thompson, Stamatiki Kritas, Richard Heddle, Robert JL Fraser, Taher I Omari
Charles Cock, Laura K Besanko, Carly M Burgstad, Alison Thompson, Richard Heddle, Robert JL Fraser, Investigation and Procedures Unit, Repatriation General Hospital, Daw Park, South Australia 5041, Australia
Charles Cock, Robert JL Fraser, Taher I Omari, Department of Gastroenterology and Hepatology, Flinders University of South Australia, Adelaide, South Australia 5042, Australia.
Stamatiki Kritas, Taher I Omari, Gastroenterology Unit, Women’s and Children’s Health Network, North Adelaide, South Australia 5006, Australia
Taher I Omari, Human Physiology, School of Medicine, Flinders University of South Australia, Adelaide, South Australia 5042, Australia
Author contributions: Cock C, Fraser RJL and Omari TI designed the research; Cock C, Besanko LK, Burgstad CM, Thompson A, Kritas S and Omari TI conducted the studies; Cock C and Besanko LK analyzed the data, Cock C and Besanko LK wrote the manuscript; Burgstad CM, Heddle R, Fraser RJL and Omari TI provided critical revision of the manuscript; Cock C is the guarantor of the published work; all authors approved the final version of the manuscript for publication.
Institutional review board statement: The study was reviewed and approved by the Southern Adelaide Clinical Human Ethics Committee (Approval 403/10).
Informed consent statement: All subjects provided written informed consent prior to participating in the study.
Conflict-of-interest statement: There are no conflicts of interest. Professor Omari owns a patent on AIM pressure flow analysis methods, which are not reported on for this study.
Data sharing statement: Data used in the study are available on request from Dr Cock. Details of esophageal manometry data in these subjects have been published separately.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Charles Cock, FRACP, Director, Investigation and Procedures Unit, Repatriation General Hospital, Daws Road Rd, Daw Park, South Australia 5041, Australia. charles.cock@flinders.edu.au
Telephone: +61-8-82751977 Fax: +61-8-82751083
Received: December 21, 2016
Peer-review started: December 23, 2016
First decision: January 10, 2017
Revised: January 27, 2017
Accepted: March 20, 2017
Article in press: March 20, 2017
Published online: April 21, 2017
AIM
To investigate the functional effects of abnormal esophagogastric (EGJ) measurements in asymptomatic healthy volunteers over eighty years of age.
METHODS
Data from 30 young controls (11 M, mean age 37 ± 11 years) and 15 aged subjects (9 M, 85 ± 4 years) were compared for novel metrics of EGJ-function: EGJ-contractile integral (EGJ-CI), “total” EGJ-CI and bolus flow time (BFT). Data were acquired using a 3.2 mm, 25 pressure (1 cm spacing) and 12 impedance segment (2 cm) solid-state catheter (Unisensor and MMS Solar GI system) across the EGJ. Five swallows each of 5 mL liquid (L) and viscous (V) bolus were analyzed. Mean values were compared using Student’s t test for normally distributed data or Mann Whitney U-test when non-normally distributed. A P value < 0.05 was considered significant.
RESULTS
EGJ-CI at rest was similar for older subjects compared to controls. “Total” EGJ-CI, measured during liquid swallowing, was increased in older individuals when compared to young controls (O 39 ± 7 mmHg.cm vs C 18 ± 3 mmHg.cm; P = 0.006). For both liquid and viscous bolus consistencies, IRP4 was increased (L: 11.9 ± 2.3 mmHg vs 5.9 ± 1.0 mmHg, P = 0.019 and V: 14.3 ± 2.4 mmHg vs 7.3 ± 0.8 mmHg; P = 0.02) and BFT was reduced (L: 1.7 ± 0.3 s vs 3.8 ± 0.2 s and V: 1.9 ± 0.3 s vs 3.8 ± 0.2 s; P < 0.001 for both) in older subjects, when compared to young. A matrix of bolus flow and presence above the EGJ indicated reductions in bolus flow at the EGJ occurred due to both impaired bolus transport through the esophageal body (i.e., the bolus never reached the EGJ) and increased flow resistance at the EGJ (i.e., the bolus retained just above the EGJ).
CONCLUSION
Bolus flow through the EGJ is reduced in asymptomatic older individuals. Both ineffective esophageal bolus transport and increased EGJ resistance contribute to impaired bolus flow.
Core tip: Disturbances in esophagogastric junction (EGJ) relaxation have previously been described in extreme older age (> 80 years). The functional consequences of such observations are not known. We investigated several novel metrics of EGJ function - EGJ-contractile integral (EGJ-CI), “total” EGJ-CI during swallowing and EGJ bolus flow time - in young controls and asymptomatic healthy older volunteers (> 80 years). Our findings indicate reduced swallow-induced EGJ relaxation and decreased EGJ bolus flow in older subjects. These findings confirm functional consequences for observations such as increased IRP measurements in older subjects and that caution applies when interpreting EGJ metrics in older patients.
